6

I've two windows machine and trying to SSH using CYGWIN. It works fine when password prompted. However, when I generated the private/public pair, looks like authentication succeeded, but got the connection closed error.

Here's the detail logs: Please help

debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug3: start over, passed a different list publickey,password,keyboard-interactive
debug3: preferred publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /home/502537203/.ssh/id_rsa
debug3: send_pubkey_test
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug1: Authentication succeeded (publickey).
Authenticated to hostname ([x.x.x.x]:22).
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug3: send packet: type 90
debug1: Requesting [email protected]
debug3: send packet: type 80
debug1: Entering interactive session.
debug1: pledge: network
debug3: send packet: type 1
debug1: channel 0: free: client-session, nchannels 1
debug3: channel 0: status: The following connections are open:
  #0 client-session (t3 r-1 i0/0 o0/0 fd 4/5 cc -1)

Connection to hostname closed by remote host.
Connection to hostname closed.
Transferred: sent 2056, received 1500 bytes, in 0.0 seconds
debug1: Exit status -1
Improve this question
5
  • I generated this log via ssh -vvv to the remote server and also placed the authorized_keys as well
    – Kamal
    Commented Nov 16, 2016 at 18:34
  • 1
    You're doing your part just fine, it's the remote server that closes the connection. Look at the logs of the remote machine.
    – Satō Katsura
    Commented Nov 16, 2016 at 18:42
  • In which location of the server, I need to check for logs.
    – Kamal
    Commented Nov 16, 2016 at 19:11
  • Check under \cygwin\var\log\messages
    – stark
    Commented Nov 16, 2016 at 19:14
  • I've only below four files under /var/log -> setup.log, setup.log.full, sshd.log (no data), lastlog (huge data). Which one to check?
    – Kamal
    Commented Nov 16, 2016 at 19:22

3 Answers 3

Reset to default
2

It's working now. I did the following

  1. set the permission for ~/.ssh 0700
  2. all the files under ~/.ssh 0600
  3. run the sshd service as cyg_server id (created during ssh-host-config)
  4. edit /etc/sshd_config to allow PubkeyAuthentication yes
Improve this answer
1
  • 3
    There is a debug1: Authentication succeeded (publickey)., so this and the other answers are wrong (for this specific case)
    – Giacomo Catenazzi
    Commented Jan 14, 2020 at 13:02
0

Incompatible ciphers can get negotiated. Try this:

ssh -oCiphers=aes128-ctr user@host

http://developer.toradex.com/knowledge-base/ssh#incompatible-cipher-support

Improve this answer
0

I saw the same error when i tried to ssh to Synology, as i needed to use Borg Backup. The problem was that i was trying to connect TO a user that wasn't the admin, even though all permissions were correct. When i tried to ssh to the user that was superadmin, connection was not dropped. I don't know if this helps, but this is my experience with this error.

Improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .